Welding burn remover

ABSTRACT

A welding burn remover includes: a mover including a movable body to which a support of an electrolytic end effector is attached and at least one actuator that moves the movable body; and processing circuitry configured to control the actuator. The processing circuitry is configured to execute an electrolytic treatment in which the processing circuitry controls the actuator to slide an electrode on a welding burn portion of a welded workpiece through a short-circuit prevention cover while controlling a pump to supply an electrolytic solution to a boundary by an electrolytic solution feeder. The support of the electrolytic end effector includes: a base attached to the movable body of the mover; and a coupler connecting the electrode to the base such that the electrode is angularly displaceable relative to the base.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Japanese Patent Application No. 2022-090741 filed on Jun. 3, 2022, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a welding burn remover.

2. Description of the Related Art

Japanese Laid-Open Utility Model Application Publication No. 4-48271 discloses a device that performs electrolytic removal of welding burns of metal, such as stainless steel, by electrochemical action. This device includes a grip, an electrode located at a tip of the grip, and a short-circuit prevention member that covers the electrode and is made of cloth or porous ceramic. A worker holds the grip and slides the electrode on a welding burn portion of a welded workpiece through the short-circuit prevention member while an electrolytic solution is supplied to a boundary between the short-circuit prevention member and the welded workpiece.

However, when the welded workpiece is large, and the welding burn portion exists in a wide range, the workload of the worker is large. Moreover, even in the case of automating the work of removing the welding burns, the surface of the welded workpiece may be distorted or deformed, and the control may be complex.

An object of one aspect of the present disclosure is to automate work of removing a welding burn by an electrolytic treatment without complex control.

SUMMARY OF THE INVENTION

A welding burn remover according to one aspect of the present disclosure includes: an electrolytic end effector including an electrode, a support supporting the electrode, and a non-conductive short-circuit prevention cover covering the electrode and including holes; an electrolytic solution feeder including a supply passage through which an electrolytic solution is supplied to a boundary between a welding burn portion on a surface of a welded workpiece and the short-circuit prevention cover and a pump that supplies the electrolytic solution to the supply passage; a mover including a movable body to which the support of the electrolytic end effector is attached and at least one actuator that moves the movable body; and processing circuitry configured to control the actuator. The processing circuitry is configured to execute an electrolytic treatment in which the processing circuitry controls the actuator to slide the electrode on the welding burn portion of the welded workpiece through the short-circuit prevention cover while controlling the pump to supply the electrolytic solution to the boundary by the electrolytic solution feeder. The support of the electrolytic end effector includes a base attached to the movable body of the mover and a coupler connecting the electrode to the base such that the electrode is angularly displaceable relative to the base.

According to one aspect of the present disclosure, when the mover slides the electrode of the electrolytic end effector on the surface of the welded workpiece, the electrode is angularly displaceable relative to the base, and therefore, the electrode can smoothly follow the surface of the welded workpiece which is distorted or deformed. On this account, the removal work of the welding burns by the electrolytic treatment can be automated without complex control.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a welding burn remover according to an embodiment.

FIG. 2 is a perspective view of the welding burn remover of FIG. 1 from another angle.

FIG. 3 is a front view of the welding burn remover of FIG. 1 .

FIG. 4 is a side view of the welding burn remover of FIG. 1 .

FIG. 5 is a perspective view of an electrolytic end effector of FIG. 1 .

FIG. 6 is a sectional view of major components of the electrolytic end effector of FIG. 5 .

FIG. 7 is a block diagram of a controller of the welding burn remover of FIG. 1 .

FIG. 8 is an enlarged perspective view of a welding burn portion of a side bodyshell.

FIG. 9 is a sectional view of major components for explaining an electrolytic treatment performed by the welding burn remover of FIG. 1 .

FIG. 10A is a diagram for explaining First Example of a sliding pattern of an electrode with respect to the welding burn portions. FIG. 10B is a diagram for explaining Second Example of the sliding pattern of the electrode with respect to the welding burn portions. FIG. 10C is a diagram for explaining Third Example of the sliding pattern of the electrode with respect to the welding burn portions. FIG. 10D is a diagram for explaining Fourth Example of the sliding pattern of the electrode with respect to the welding burn portions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment will be described with reference to the drawings. In the following description, an X direction (second direction) denotes a horizontal direction, a Y direction (third direction) denotes an upper-lower direction, and a Z direction (first direction) denotes a direction orthogonal to the X direction and the Y direction.

FIG. 1 is a perspective view of a welding burn remover 1 according to the embodiment. FIG. 2 is a perspective view of the welding burn remover 1 of FIG. 1 from another angle. As shown in FIGS. 1 and 2 , the welding burn remover 1 is a device that removes a welding burn portion on a surface of a welded workpiece by an electrolytic treatment. The welded workpiece is, for example, a side bodyshell 90 of a railcar. The side bodyshell 90 is a plate-shaped structural body in which members are welded to each other in the Z direction.

Specifically, the side bodyshell 90 includes an outside plate 91 and frame members 92 welded to a back surface of the outside plate 91. The frame members 92 include vertical frame members extending in the upper-lower direction and lateral frame members extending in the horizontal direction. The outside plate 91 includes a window opening H1 and an auxiliary opening H2. The side bodyshell 90 includes a bent portion 90 a extending in the horizontal direction. To be specific, in the side bodyshell 90, a first portion 90 b located at a lower side of the bent portion 90 a and a second portion 90 c located at an upper side of the bent portion 90 a extend at different angles. The bent shape of the outside plate 91, the shapes and arrangement of the frame members 92, the shapes and arrangement of the openings H1 and H2, and the like may differ depending on the type of the side bodyshell 90.

The welding burn remover 1 includes a jig 2 at which the side bodyshell 90 is placed. The jig 2 supports the side bodyshell 90 that is placed vertically. Specifically, the jig 2 includes: a first frame 11 placed on a ground surface; and a second frame 12 projecting upward from the first frame 11. The second frame 12 includes a lower support frame 13 and a side support frame 14. The lower support frame 13 supports a lower end of the side bodyshell 90 from below. The side support frame 14 is located above the lower support frame 13 and supports, from a lateral side, an inner surface of the side bodyshell 90, i.e., the surface where the frame members 92 exist.

The welding burn remover 1 includes a mover 3 that moves electrolytic end effectors 4. The mover 3 includes: an X-axis guide 21 placed on the ground surface and extending in the X direction; and a movable unit 22 that is movable in the X direction along the X-axis guide 21. The X-axis guide 21 is, for example, a linear guide. The movable unit 22 is supported by the X-axis guide 21 so as to be slidable in the X direction. The movable unit 22 includes: a base portion 31 supported by the X-axis guide 21; and a columnar portion 32 projecting upward from the base portion 31.

The mover 3 includes one X-axis actuator 23, two Y-axis actuators 24, and two Z-axis actuators 25. Each of the number of Y-axis actuators 24 and the number of Z-axis actuators 25 is equal to the number of electrolytic end effectors 4. In the present embodiment, the number of electrolytic end effectors 4 is two, but may be one or may be three or more.

The X-axis actuator 23 is, for example, a rack-and-pinion electric driver. The X-axis actuator 23 includes an X-axis motor 33, a rack 34, and a pinion (not shown). The X-axis motor 33 is placed at the base portion 31 of the movable unit 22 and rotates the pinion. The rack 34 extends in parallel with the X-axis guide 21, The pinion meshing with the rack 34 is rotated by the X-axis motor 33. With this, the movable unit 22 moves in the X direction along the X-axis guide 21. Therefore, the electrolytic end effectors 4 supported by the movable unit 22 move in the X direction.

The Y-axis actuators 24 are, for example, electric linear actuators. Each of the Y-axis actuators 24 includes a Y-axis motor 35 and a ball screw mechanism 36 extending in the Y direction and driven by the Y-axis motor 35. A Y-axis movable body 37 is connected to the ball screw mechanism 36. When the ball screw mechanism 36 is driven by the Y-axis motor 35 to operate, the Y-axis movable body 37 moves in the Y direction in association with the ball screw mechanism 36. With this, the electrolytic end effector 4 supported by the Y-axis movable body 37 moves in the Y direction. The Y direction does not have to be a completely vertical direction as long as it is directed in the upper-lower direction. The Z-axis actuators 25 will be described later with reference to FIG. 5 .

FIG. 3 is a front view of the welding burn remover 1 of FIG. 1 . As shown in FIG. 3 , the lower support frame 13 of the jig 2 includes positioning portions 13 a. The positioning portions 13 a are, for example, projections projecting upward. The frame members 92 (see FIG. 2 ) of the side bodyshell 90 include internal spaces that are open downward. The positioning portions 13 a are inserted into the internal spaces from below.

The welding burn remover 1 includes a waste liquid receiver 6 located right under the lower support frame 13. To be specific, the waste liquid receiver 6 is located right under the side bodyshell 90 placed at the jig 2. The waste liquid receiver 6 is a container that extends in the X direction and is open upward. A bottom surface of the waste liquid receiver 6 is inclined relative to the horizontal direction. A drain tube 7 is connected to a lowermost portion of the bottom surface of the waste liquid receiver 6. An electrolytic solution having fallen down along the side bodyshell 90, i.e., a waste liquid is received by the waste liquid receiver 6. The waste liquid accumulated in the waste liquid receiver 6 is guided through the drain tube 7 to a predetermined place.

FIG. 4 is a side view of the welding burn remover 1 of FIG. 1 . As shown in FIG. 4 , the side bodyshell 90 has a bent shape, i.e., is bent at the bent portion 90 a when viewed in the X direction. The side support frame 14 of the jig 2 includes a first supporting portion 14 a and a second supporting portion 14 b. The first supporting portion 14 a supports the first portion 90 b located at the lower side of the bent portion 90 a in the side bodyshell 90, and the second supporting portion 14 b supports the second portion 90 c located at the upper side of the bent portion 90 a in the side bodyshell 90. The first supporting portion 14 a and the second supporting portion 14 b are opposed to the frame members 92 of the side bodyshell 90 and support the side bodyshell 90 from a lateral side.

An angle between the first supporting portion 14 a and the second supporting portion 14 b in the side support frame 14 is adjustable. The angle between the first supporting portion 14 a and the second supporting portion 14 b is set to be equal to an angle between the first portion 90 b and the second portion 90 c in the side bodyshell 90. To be specific, the first supporting portion 14 a and the second supporting portion 14 b are portions of the jig 2 which have shapes corresponding to the bent shape of the side bodyshell 90. The side bodyshell 90 that has been placed vertically on the lower support frame 13 is inclined relative to the vertical direction and leans against the side support frame 14.

An identification sensor 5 that identifies the type of the side bodyshell 90 placed at the jig 2 is located at the side support frame 14. The shape of the side bodyshell 90 differs depending on the type. To identify the type of the side bodyshell 90, the identification sensor 5 detects the shape of the side bodyshell 90 placed at the jig 2. For example, the identification sensor 5 is a proximity sensor. The arrangement of the frame members 92 of the side bodyshell 90 differs depending on the type. The identification sensor 5 detects the frame members 92 of the side bodyshell 90 placed at the jig 2.

FIG. 5 is a perspective view of the electrolytic end effector 4 of FIG. 1 . As shown in FIG. 5 , the Z-axis actuator 25 is connected to the electrolytic end effector 4. The Z-axis actuator 25 is, for example, an electric linear actuator. The Z-axis actuator 25 includes a Z-axis motor 38 and a ball screw mechanism 39 extending in the Z direction and driven by the Z-axis motor 38. A Z-axis movable body 40 is connected to the ball screw mechanism 39. When the ball screw mechanism 39 is driven by the Z-axis motor 38 to operate, the Z-axis movable body 40 moves in the Z direction in association with the ball screw mechanism 39. With this, the electrolytic end effector 4 supported by the Z-axis movable body 40 moves in the Z direction.

The electrolytic end effector 4 includes an electrode 41, a support 42 supporting the electrode 41, and a short-circuit prevention cover 43 covering the electrode 41. The electrode 41 is made of metal. The electrode 41 includes an electrode surface 41 a that is directed in the Z direction and opposed to a surface 91 a (see FIG. 1 ) of the outside plate 91 of the side bodyshell The electrode surface 41 a includes a flat surface. The electrode 41 has a rectangular shape extending in the Y direction. The short-circuit prevention cover 43 covers the electrode 41. The short-circuit prevention cover 43 is made of a non-conductive material and includes holes. The short-circuit prevention cover 43 may be made of a fibrous material, such as cloth, or a porous ceramic material.

The support 42 is connected to the Z-axis movable body 40 and supports the electrode 41. The support 42 includes: a base 51 attached to the Z-axis movable body 40; and a coupler 52 connecting the electrode 41 to the base 51 such that the electrode 41 is angularly displaceable relative to the base 51. The coupler 52 includes a pivot shaft 53 and a bracket 54. The pivot shaft 53 extends in the X direction and is supported by the base 51. The bracket 54 supports the pivot shaft 53 such that the pivot shaft 53 is turnable. The bracket 54 is connected to the electrode 41. The electrode 41 is angularly displaceable about the pivot shaft 53.

A displacement sensor 67 is attached to the base 51. The displacement sensor 67 detects a distance between the electrode 41 and the side bodyshell 90 in the Z direction. An electric wire 68 connected to a power supply circuit 65 is connected to the bracket 54. The electrode 41 is supplied with electric power from the power supply circuit 65 through the bracket 54 and the electric wire 68.

An electrolytic feeder 8 is connected to the short-circuit prevention cover 43 (or the electrode 41). The electrolytic feeder 8 includes a supply tube 61 and a pump 62. The supply tube 61 connects an electrolytic solution tank 9 to the short-circuit prevention cover 43. The supply tube 61 includes a supply passage 61 a through which the electrolytic solution is supplied from the electrolytic solution tank 9 to the short-circuit prevention cover 43. The electrolytic solution tank 9 stores the electrolytic solution. The electrolytic solution tank 9 may be located at, for example, the movable unit 22 (see FIG. 1 ).

The pump 62 supplies the electrolytic solution, stored in the electrolytic solution tank 9, through the supply passage 61 a to the short-circuit prevention cover 43. An electrolytic solution sensor 63 is located at the electrolytic feeder 8 and can detect the flow of the electrolytic solution in the supply passage 61 a. The electrolytic solution sensor 63 may be, for example, a flow rate sensor located at the supply tube 61.

FIG. 6 is a sectional view of major components of the electrolytic end effector 4 of FIG. 5 . As shown in FIG. 6 , the electrode 41 is turnable about the pivot shaft 53. The coupler 52 does not include any pivot shaft except for the pivot shaft 53. To be specific, the coupler 52 connects the electrode 41 to the base 51 so as to prevent the electrode 41 from being angularly displaced about the Y direction.

The coupler 52 of the electrolytic end effector 4 includes a pair of pins 55A and 55B and a pair of elastic bodies 56A and 56B. The elastic body 56A pushes the bracket 54 through the pin 55A in such a direction that the bracket 54 rotates in one direction around the pivot shaft 53. The elastic body 56B pushes the bracket 54 through the pin 55B in such a direction that the bracket 54 rotates in the other direction around the pivot shaft 53. The elastic bodies 56A and 56B bias the electrode 41 through the pins 55A and 55B and the bracket 54 such that when the electrode 41 rotates about the pivot shaft 53, the electrode 41 returns to a neutral posture in which the electrode surface 41 a is orthogonal to the Z direction.

FIG, 7 is a block diagram of a controller 10 of the welding burn remover 1 of FIG. 1 . In FIG. 1 , the controller 10 is not shown. As shown in FIG. 7 , the identification sensor 5, a user interface 66, the electrolytic solution sensor 63, and the displacement sensor 67 are connected to an input side of the controller 10. The X-axis motor 33, the Y-axis motor 35, the Z-axis motor 38, the pump 62, and the power supply circuit 65 are connected to an output side of the controller 10.

The controller 10 includes a processor and a memory. Specifically, the controller includes a processor 71, a system memory 72, a storage memory 73, and the like. The processor 71 is, for example, a central processing unit. The system memory 72 is, for example, a RAM. The storage memory 73 is an example of a computer-readable medium and is a non-transitory and tangible medium. The storage memory 73 may include a ROM. The storage memory 73 stores a program. A configuration in which the processor 71 executes the program read in the system memory 72 is one example of processing circuitry.

A movement pattern of the electrolytic end effector 4 is determined based on a control pattern of the X-axis motor 33, the Y-axis motor 35, and the Z-axis motor 38. As the control pattern of the motors 33, 35, and 38, the storage memory 73 includes control patterns different from each other. These control patterns are stored so as to be associated with the types of the side bodyshell 90. Each control pattern specifies a movement route of the electrolytic end effector 4 in accordance with the shape of the side bodyshell 90 such that the movement route avoids the openings H1 and H2 of the side bodyshell 90.

When a worker inputs a start command through the user interface 66, the controller 10 determines the type of the side bodyshell 90 placed at the jig 2 based on a detection signal of the identification sensor 5. The controller 10 selects the control pattern corresponding to the determined type from the control patterns stored in the storage memory 73 and starts the electrolytic treatment in accordance with the selected control pattern.

In the electrolytic treatment, the controller 10 controls the motors 33, 35, and 38 in accordance with the selected control pattern. When controlling the Z-axis motor 38, the controller 10 adjusts an operation amount of the Z-axis motor 38 based on a detection signal of the displacement sensor 67. In the electrolytic treatment, the controller 10 controls the power supply circuit 65 to supply electric power to the electrode 41 (see FIG. 9 ) and drives the pump 62. When the electrolytic solution sensor 63 detects that the electrolytic solution is not flowing through the supply passage 61 a (see FIG. 6 ), the controller 10 stops the electrolytic treatment and outputs information.

FIG. 8 is an enlarged perspective view of a welding burn portion Wa of the side bodyshell 90. As shown in FIG. 8 , in the side bodyshell 90, spot-shaped welded portions W exist on the surface 91 a of the outside plate 91 by spot welding of the frame members 92 with respect to the outside plate 91. The welded portions W buldge on the surface 91 a of the outside plate 91, and the welding burn portions Wa are generated around the welded portions W.

FIG. 9 is a sectional view of major components for explaining the electrolytic treatment performed by the welding burn remover 1 of FIG. 1 . As shown in FIG. 9 , in the electrolytic treatment, while controlling the pump 62 to supply the electrolytic solution through the supply tube 61 to a boundary B between the side bodyshell 90 and the electrode 41, the controller 10 (see FIG. 7 ) controls the motors 33, 35, and 38 to slide the electrode 41 on the welding burn portions Wa of the side bodyshell 90 through the short-circuit prevention cover 43.

At this time, while controlling the Z-axis motor 38 (see FIG. 5 ) to press the electrode 41 against the surface 91 a of the side bodyshell 90 in the Z direction, the controller 10 (see FIG. 7 ) controls the X-axis motor 33 (see FIG. 1 ) to advance the electrode 41 in the X direction. With this, the welding burn portions Wa existing on the surface 91 a of the side bodyshell 90 in a wide range are efficiently removed by the electrolytic treatment. The controller 10 performs torque control of the Z-axis motor 38 such that the electrode 41 presses the surface 91 a of the side bodyshell 90 by a constant load. However, the load may be controlled to be constant in such a manner that a load sensor is located at the electrolytic end effector 4 and detects the load applied from the electrode 41 to the surface 91 a.

Even when the surface 91 a of the outside plate 91 is distorted or deformed, the electrode 41 is elastically and angularly displaced relative to the base 51 about the pivot shaft 53, and with this, the electrode 41 smoothly follows the surface 91 a of the side bodyshell 90. Since the electrode 41 has a shape extending in the Y direction, the electrode 41 slides on the welded portions Wa at the same time. With this, the surface 91 a of the side bodyshell 90 is subjected to the electrolytic treatment in a wide range, and therefore, a time required for the removal of the welding burns is shortened. Moreover, sliding the electrode surface 41 a on the entire side bodyshell 90 is effective for not only the removal of the welding burns but also the surface finish of the side bodyshell 90.

FIG. 10A is a diagram for explaining First Example of a sliding pattern of the electrode 41 with respect to the welding burn portions Wa. As shown in FIG. 10A, in First Example, the controller 10 (see FIG. 7 ) does not drive the Y-axis motor 35 (see FIG. 1 ) but drives the X-axis motor 33 (see FIG. 1 ) to linearly move the electrode 41 in the X direction. According to this sliding pattern, when the welding burns are relatively easily removed by the electrolytic treatment, welding burn removal work can be completed in a short period of time.

FIG. 10B is a diagram for explaining Second Example of the sliding pattern of the electrode 41 with respect to the welding burn portions Wa. FIG. 10C is a diagram for explaining Third Example of the sliding pattern of the electrode 41 with respect to the welding burn portions Wa. As shown in FIGS. 10B and 10C, in Second Example and Third Example, the controller 10 (see FIG. 7 ) drives the X-axis motor 33 (see FIG. 1 ) to move the electrode 41 in the X direction while driving the Y-axis motor 35 (see FIG. 1 ) to reciprocate the electrode 41 in the Y direction. According to this sliding pattern, since the electrode 41 multidirectionally accesses the welding burn portions Wa through the short-circuit prevention cover 43 (see FIG. 9 ), the welding burns can be removed uniformly.

FIG. 10D is a diagram for explaining Fourth Example of the sliding pattern of the electrode 41 with respect to the welding burn portions Wa. As shown in FIG. 10D, in Fourth Example, while driving the Y-axis motor 35 (see FIG. 1 ) to reciprocate the electrode 41 in the Y direction, the controller 10 (see FIG. 7 ) drives the X-axis motor 33 (see FIG. 1 ) such that the electrode 41 moves in the X direction while repeatedly advancing and retreating in the X direction. According to this sliding pattern, since the electrode 41 multidirectionally and repeatedly accesses the welding burn portions Wa through the short-circuit prevention cover 43 (see FIG. 9 ), the welding burns can be removed uniformly.

The technology of the present disclosure is not limited to the above embodiment. For example, the welded workpiece is not limited to the side bodyshell 90 of the railcar and may be anything on which the welding burns are generated. A method of welding the side bodyshell 90 is not limited to the spot welding and may be another welding method (for example, laser welding). The mover 3 may be an articulated robot that holds the electrolytic end effector 4. The electrolytic solution sensor 63 may be a sensor that detects a remaining amount of the electrolytic solution tank 9. Instead of the pins 55A and 5513 and the elastic bodies 56A and 56B, a torsion spring located around the pivot shaft 53 may be used. The identification sensor 5 may be a two-dimensional code reader or may be a camera that takes an image in order to determine the type from the shape by image processing.

As described above, the embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this and is also applicable to embodiments in which modifications, replacements, additions, omissions, and the like are suitably made. Moreover, a new embodiment may be prepared by combining the components described in the above embodiment. For example, some of components or methods in one embodiment may be applied to another embodiment. Some components in an embodiment may be separated and arbitrarily extracted from the other components in the embodiment. Furthermore, the components shown in the attached drawings and the detailed explanations include not only components essential to solve the problems but also components for exemplifying the above technology and not essential to solve the problems.

The functionality of the elements related to the control disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, ASICs (“Application Specific Integrated Circuits”), conventional circuitry and/or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. The processor may be a programmed processor which executes a program stored in a memory. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, means, or units are a combination of hardware and software, the software being used to configure the hardware and/or processor.

Each of the following aspects discloses a preferred embodiment.

First Aspect

A welding burn remover including:

-   -   an electrolytic end effector including         -   an electrode,         -   a support supporting the electrode, and         -   a non-conductive short-circuit prevention cover covering the             electrode and including holes;     -   an electrolytic solution feeder including         -   a supply passage through which an electrolytic solution is             supplied to a boundary between a welding burn portion on a             surface of a welded workpiece and the short-circuit             prevention cover and         -   a pump that supplies the electrolytic solution to the supply             passage;     -   a mover including         -   a movable body to which the support of the electrolytic end             effector is attached and         -   at least one actuator that moves the movable body; and     -   processing circuitry configured to control the actuator,         wherein:     -   the processing circuitry is configured to execute an         electrolytic treatment in which the processing circuitry         controls the actuator to slide the electrode on the welding burn         portion of the welded workpiece through the short-circuit         prevention cover while controlling the pump to supply the         electrolytic solution to the boundary by the electrolytic         solution feeder; and     -   the support of the electrolytic end effector includes         -   a base attached to the movable body of the mover and         -   a coupler connecting the electrode to the base such that the             electrode is angularly displaceable relative to the base.

According to this configuration, when the mover slides the electrode of the electrolytic end effector on the surface of the welded workpiece, the electrode is angularly , displaceable relative to the base, and therefore, the electrode can smoothly follow the surface of the welded workpiece which is distorted or deformed. On this account, the removal work of the welding burns by the electrolytic treatment can be automated without complex control,

Second Aspect

The welding burn remover according to the first aspect, wherein the processing circuitry is configured to control the actuator to advance the electrode in a second direction while pressing the electrode against the surface of the welded workpiece in a first direction intersecting with the surface of the welded workpiece.

According to this configuration, the welding burns existing in a wide range on the surface of the welded workpiece can be efficiently removed.

Third Aspect

The welding burn remover according to the first or second aspect, wherein the electrode includes an electrode surface that extends in a third direction orthogonal to the first direction and the second direction and is opposed to the surface of the welded workpiece.

According to this configuration, when the electrode advances in the second direction, the surface of the welded workpiece can be subjected to the electrolytic treatment in a wide range in the third direction orthogonal to the first direction and the second direction. Therefore, a time required for the removal of the welding burns can be shortened.

Fourth Aspect

The welding burn remover according to the second or third aspect, wherein the coupler includes a pivot shaft extending in the second direction.

According to this configuration, the electrode is angularly displaceable about the pivot shaft extending in the second direction that is an advancing direction of the electrode. Therefore, the electrode is swingable in the third direction orthogonal to the first direction and the second direction and can smoothly follow curves in the third direction on the surface of the welded workpiece. On this account, even when the welded workpiece is distorted, the welding burns can be removed uniformly.

Fifth Aspect

The welding burn remover according to the fourth aspect, wherein:

-   -   the electrode includes an electrode surface opposed to the         surface of the welded workpiece;     -   the electrode surface includes a flat surface; and     -   the coupler further includes an elastic body that biases the         electrode toward a neutral posture in which the flat surface is         orthogonal to the first direction.

According to this configuration, even when the electrode is angularly displaced along the curves on the surface of the welded workpiece, the electrode surface presses the surface of the welded workpiece in a well-balanced manner. Therefore, even when the welded workpiece is distorted, the welding burns can be removed uniformly.

Sixth Aspect

The welding burn remover according to any one of the second to fifth aspects, wherein the coupler connects the electrode to the base such that the electrode is prevented from being angularly displaced about a third direction orthogonal to the first direction and the second direction.

According to this configuration, since the electrode does not swing in the advancing direction of the electrode, the electrode can be stably pressed against the surface of the welded workpiece during the sliding of the electrode. Therefore, even when the electrode is angularly displaceable relative to the base, the welding burns can be uniformly removed.

Seventh Aspect

The welding burn remover according to any one of the second to sixth aspects, wherein the processing circuitry is configured to control the actuator to reciprocate the electrode in a third direction orthogonal to the first direction and the second direction while the electrode advances in the second direction.

According to this configuration, since the electrode multidirectionally accesses the welding burn portions of the welded workpiece through the short-circuit prevention cover, the welding burns can be removed uniformly.

Eighth Aspect

The welding burn remover according to any one of the second to seventh aspects, further including a jig at which the welded workpiece is placed, wherein:

-   -   the welded workpiece is a plate-shaped structural body;     -   the jig supports the welded workpiece that is placed vertically;         and     -   a third direction orthogonal to the first direction and the         second direction is an upper-lower direction.

According to this configuration, the plate-shaped welded workpiece that is being vertically stored for space saving can be placed at the jig while maintaining such posture. Since the welded workpiece can be placed at the jig without turning over the welded workpiece, the ease of work improves, and the possibility of damages of the welded workpiece can be reduced. Moreover, since the plate-shaped welded workpiece is placed vertically, the electrolytic solution does not accumulate on the welded workpiece, and the welded workpiece can be finished with excellent quality.

Ninth Aspect

The welding burn remover according to any one of the second to eighth aspects, further including a jig at which the welded workpiece is placed, wherein:

-   -   the welded workpiece is a plate-shaped structural body including         a bent shape; and     -   the jig includes a portion that supports the welded workpiece in         a horizontal direction and includes a shape corresponding to the         bent shape of the welded workpiece.

According to this configuration, even when the welded workpiece includes the bent shape, the electrode can be pressed against the welded workpiece at an appropriate angle, and therefore, the welding burns can be removed evenly.

Tenth Aspect

The welding burn remover according to any one of the first to ninth aspects, further including an electrolytic solution sensor that detects a flow of the electrolytic solution in the supply passage, wherein

-   -   the processing circuitry is configured to stop the electrolytic         treatment when the processing circuitry determines based on a         detection signal of the electrolytic solution sensor that the         flow of the electrolytic solution in the supply passage has         stopped.

According to this configuration, when the electrolytic solution is not supplied, the electrolytic end effector can be automatically prevented from sliding on the welded workpiece. Therefore, the quality of the automated electrolytic treatment can be improved.

Eleventh Aspect

The welding burn remover according to any one of the first tenth aspects, further including:

-   -   a jig at which the welded workpiece is placed; and     -   an identification sensor that identifies a type of the welded         workpiece placed at the jig, wherein:     -   the processing circuitry is configured to         -   store control patterns of the actuator,         -   determine the type of the welded workpiece placed at the jig             based on a detection signal of the identification sensor,             and         -   select the control pattern corresponding to the determined             type from the control patterns and execute the selected             control pattern.

According to this configuration, even when the welding burn removal work is performed with respect to the welded workpieces which are different in type from each other, the control pattern appropriate for each type of the welded workpiece placed on the jig is selected. Therefore, even when the type of the welded workpiece changes, the removal work of the welding burns can be appropriately performed.

Twelfth Aspect

The welding burn remover according to any one of the first to eleventh aspects, further including:

-   -   a jig at which the welded workpiece is placed; and     -   a waste liquid receiver located under the welded workpiece         placed at the jig.

According to this configuration, since the electrolytic solution having fallen down along the welded workpiece after being used in the electrolytic treatment is received by the waste liquid receiver, the used electrolytic solution can be prevented from contaminating a working environment. 

What is claimed is:
 1. A welding burn remover comprising: an electrolytic end effector including an electrode, a support supporting the electrode, and a non-conductive short-circuit prevention cover coveting the electrode and including holes; an electrolytic solution feeder including a supply passage through which an electrolytic solution is supplied to a boundary between a welding burn portion on a surface of a welded workpiece and the short-circuit prevention cover and a pump that supplies the electrolytic solution to the supply passage; a mover including a movable body to which the support of the electrolytic end effector is attached and at least one actuator that moves the movable body; and processing circuitry configured to control the actuator, wherein: the processing circuitry is configured to execute an electrolytic treatment in which the processing circuitry controls the actuator to slide the electrode on the welding burn portion of the welded workpiece through the short-circuit prevention cover while controlling the pump to supply the electrolytic solution to the boundary by the electrolytic solution feeder; and the support of the electrolytic end effector includes a base attached to the movable body of the mover and a coupler connecting the electrode to the base such that the electrode is angularly displaceable relative to the base.
 2. The welding burn remover according to claim 1, wherein the processing circuitry is configured to control the actuator to advance the electrode in a second direction while pressing the electrode against the surface of the welded workpiece in a first direction intersecting with the surface of the welded workpiece.
 3. The welding burn remover according to claim 2, wherein the electrode includes an electrode surface that extends in a third direction orthogonal to the first direction and the second direction and is opposed to the surface of the welded workpiece.
 4. The welding burn remover according to claim 2, wherein the coupler includes a pivot shaft extending in the second direction.
 5. The welding burn remover according to claim 4, wherein: the electrode includes an electrode surface opposed to the surface of the welded workpiece; the electrode surface includes a flat surface; and the coupler further includes an elastic body that biases the electrode toward a neutral posture in which the flat surface is orthogonal to the first direction.
 6. The welding burn remover according to claim 2, wherein the coupler connects the electrode to the base such that the electrode is prevented from being angularly displaced about a third direction orthogonal to the first direction and the second direction.
 7. The welding burn remover according to claim 2, wherein the processing circuitry is configured to control the actuator to reciprocate the electrode in a third direction orthogonal to the first direction and the second direction while the electrode advances in the second direction.
 8. The welding burn remover according to claim 2, further comprising a jig at which the welded workpiece is placed, wherein: the welded workpiece is a plate-shaped structural body; the jig supports the welded workpiece that is placed vertically; and a third direction orthogonal to the first direction and the second direction is an upper-lower direction.
 9. The welding burn remover according to claim 2, further comprising a jig at which the welded workpiece is placed, wherein: the welded workpiece is a plate-shaped structural body including a bent shape; and the jig includes a portion that supports the welded workpiece in a horizontal direction and includes a shape corresponding to the bent shape of the welded workpiece.
 10. The welding burn remover according to claim 1, further comprising an electrolytic solution sensor that detects a flow of the electrolytic solution in the supply passage, wherein the processing circuitry is configured to stop the electrolytic treatment when the processing circuitry determines based on a detection signal of the electrolytic solution sensor that the flow of the electrolytic solution in the supply passage has stopped.
 11. The welding burn remover according to claim 1, further comprising: a jig at which the welded workpiece is placed; and an identification sensor that identifies a type of the welded workpiece placed at the jig, wherein: the processing circuitry is configured to store control patterns of the actuator, determine the type of the welded workpiece placed at the jig based on a detection signal of the identification sensor, and select the control pattern corresponding to the determined type from the control patterns and execute the selected control pattern.
 12. The welding burn remover according to claim 1, further comprising: a jig at which the welded workpiece is placed; and a waste liquid receiver located under the welded workpiece placed at the jig. 